block: Make bdrv_{pread,pwrite}() return 0 on success

They currently return the value of their 'bytes' parameter on success.

Make them return 0 instead, for consistency with other I/O functions and
in preparation to implement them using generated_co_wrapper. This also
makes it clear that short reads/writes are not possible.

The few callers that rely on the previous behavior are adjusted
accordingly by hand.

Signed-off-by: Alberto Faria <afaria@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20220609152744.3891847-4-afaria@redhat.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Signed-off-by: Hanna Reitz <hreitz@redhat.com>
This commit is contained in:
Alberto Faria 2022-06-09 16:27:37 +01:00 committed by Hanna Reitz
parent 32cc71def9
commit 353a5d84b2
10 changed files with 19 additions and 31 deletions

View File

@ -222,7 +222,7 @@ static inline int cloop_read_block(BlockDriverState *bs, int block_num)
ret = bdrv_pread(bs->file, s->offsets[block_num], bytes,
s->compressed_block, 0);
if (ret != bytes) {
if (ret < 0) {
return -1;
}

View File

@ -70,7 +70,7 @@ static ssize_t block_crypto_read_func(QCryptoBlock *block,
error_setg_errno(errp, -ret, "Could not read encryption header");
return ret;
}
return ret;
return buflen;
}
static ssize_t block_crypto_write_func(QCryptoBlock *block,
@ -88,7 +88,7 @@ static ssize_t block_crypto_write_func(QCryptoBlock *block,
error_setg_errno(errp, -ret, "Could not write encryption header");
return ret;
}
return ret;
return buflen;
}

View File

@ -390,7 +390,7 @@ static int dmg_read_plist_xml(BlockDriverState *bs, DmgHeaderState *ds,
buffer = g_malloc(info_length + 1);
buffer[info_length] = '\0';
ret = bdrv_pread(bs->file, info_begin, info_length, buffer, 0);
if (ret != info_length) {
if (ret < 0) {
ret = -EINVAL;
goto fail;
}
@ -611,7 +611,7 @@ static inline int dmg_read_chunk(BlockDriverState *bs, uint64_t sector_num)
* inflated. */
ret = bdrv_pread(bs->file, s->offsets[chunk], s->lengths[chunk],
s->compressed_chunk, 0);
if (ret != s->lengths[chunk]) {
if (ret < 0) {
return -1;
}
@ -637,7 +637,7 @@ static inline int dmg_read_chunk(BlockDriverState *bs, uint64_t sector_num)
* inflated. */
ret = bdrv_pread(bs->file, s->offsets[chunk], s->lengths[chunk],
s->compressed_chunk, 0);
if (ret != s->lengths[chunk]) {
if (ret < 0) {
return -1;
}
@ -658,7 +658,7 @@ static inline int dmg_read_chunk(BlockDriverState *bs, uint64_t sector_num)
* inflated. */
ret = bdrv_pread(bs->file, s->offsets[chunk], s->lengths[chunk],
s->compressed_chunk, 0);
if (ret != s->lengths[chunk]) {
if (ret < 0) {
return -1;
}
@ -674,7 +674,7 @@ static inline int dmg_read_chunk(BlockDriverState *bs, uint64_t sector_num)
case UDRW: /* copy */
ret = bdrv_pread(bs->file, s->offsets[chunk], s->lengths[chunk],
s->uncompressed_chunk, 0);
if (ret != s->lengths[chunk]) {
if (ret < 0) {
return -1;
}
break;

View File

@ -1100,7 +1100,6 @@ int bdrv_make_zero(BdrvChild *child, BdrvRequestFlags flags)
int bdrv_pread(BdrvChild *child, int64_t offset, int64_t bytes, void *buf,
BdrvRequestFlags flags)
{
int ret;
QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes);
IO_CODE();
@ -1108,9 +1107,7 @@ int bdrv_pread(BdrvChild *child, int64_t offset, int64_t bytes, void *buf,
return -EINVAL;
}
ret = bdrv_preadv(child, offset, bytes, &qiov, flags);
return ret < 0 ? ret : bytes;
return bdrv_preadv(child, offset, bytes, &qiov, flags);
}
/* Return no. of bytes on success or < 0 on error. Important errors are:
@ -1122,7 +1119,6 @@ int bdrv_pread(BdrvChild *child, int64_t offset, int64_t bytes, void *buf,
int bdrv_pwrite(BdrvChild *child, int64_t offset, int64_t bytes,
const void *buf, BdrvRequestFlags flags)
{
int ret;
QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes);
IO_CODE();
@ -1130,9 +1126,7 @@ int bdrv_pwrite(BdrvChild *child, int64_t offset, int64_t bytes,
return -EINVAL;
}
ret = bdrv_pwritev(child, offset, bytes, &qiov, flags);
return ret < 0 ? ret : bytes;
return bdrv_pwritev(child, offset, bytes, &qiov, flags);
}
/*

View File

@ -597,7 +597,7 @@ static int decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset)
csize &= (s->cluster_size - 1);
BLKDBG_EVENT(bs->file, BLKDBG_READ_COMPRESSED);
ret = bdrv_pread(bs->file, coffset, csize, s->cluster_data, 0);
if (ret != csize)
if (ret < 0)
return -1;
if (decompress_buffer(s->cluster_cache, s->cluster_size,
s->cluster_data, csize) < 0) {

View File

@ -113,7 +113,7 @@ static ssize_t qcow2_crypto_hdr_read_func(QCryptoBlock *block, size_t offset,
error_setg_errno(errp, -ret, "Could not read encryption header");
return -1;
}
return ret;
return buflen;
}
@ -174,7 +174,7 @@ static ssize_t qcow2_crypto_hdr_write_func(QCryptoBlock *block, size_t offset,
error_setg_errno(errp, -ret, "Could not read encryption header");
return -1;
}
return ret;
return buflen;
}
static QDict*

View File

@ -87,14 +87,9 @@ static void qed_header_cpu_to_le(const QEDHeader *cpu, QEDHeader *le)
int qed_write_header_sync(BDRVQEDState *s)
{
QEDHeader le;
int ret;
qed_header_cpu_to_le(&s->header, &le);
ret = bdrv_pwrite(s->bs->file, 0, sizeof(le), &le, 0);
if (ret != sizeof(le)) {
return ret;
}
return 0;
return bdrv_pwrite(s->bs->file, 0, sizeof(le), &le, 0);
}
/**

View File

@ -730,7 +730,7 @@ nonallocating_write:
n_sectors * SECTOR_SIZE, base, 0);
}
return ret < 0 ? ret : 0;
return ret;
}
static int coroutine_fn vdi_co_do_create(BlockdevCreateOptions *create_options,

View File

@ -473,7 +473,6 @@ static int vmdk_parent_open(BlockDriverState *bs)
if (ret < 0) {
goto out;
}
ret = 0;
p_name = strstr(desc, "parentFileNameHint");
if (p_name != NULL) {
@ -905,7 +904,7 @@ static char *vmdk_read_desc(BdrvChild *file, uint64_t desc_offset, Error **errp)
g_free(buf);
return NULL;
}
buf[ret] = 0;
buf[size] = 0;
return buf;
}
@ -1630,7 +1629,7 @@ static int get_cluster_offset(BlockDriverState *bs,
l2_size_bytes,
l2_table,
0
) != l2_size_bytes) {
) < 0) {
return VMDK_ERROR;
}

View File

@ -89,7 +89,7 @@ static void test_sync_op_pread(BdrvChild *c)
/* Success */
ret = bdrv_pread(c, 0, sizeof(buf), buf, 0);
g_assert_cmpint(ret, ==, 512);
g_assert_cmpint(ret, ==, 0);
/* Early error: Negative offset */
ret = bdrv_pread(c, -2, sizeof(buf), buf, 0);
@ -103,7 +103,7 @@ static void test_sync_op_pwrite(BdrvChild *c)
/* Success */
ret = bdrv_pwrite(c, 0, sizeof(buf), buf, 0);
g_assert_cmpint(ret, ==, 512);
g_assert_cmpint(ret, ==, 0);
/* Early error: Negative offset */
ret = bdrv_pwrite(c, -2, sizeof(buf), buf, 0);